Yes, I found that out the hard way when I got a Tandy on clearance with a few Basic books, and would type out example programs for an hour or so only to have some of them not work due to some incompatibility. It was probably still a good learning experience though.
My first "real computer" (not counting the "computer" in the Milton Bradley Big Trak - though it was a form of Logo programming, I suppose) was a TRS-80 Color Computer 2 - in 1984.
My parents got it for me after I showed an interest in the Apple IIe computer that was wheeled around my elementary school at the time (yes - one computer for the whole school, each teach got it "checked out" once a month - it ended up being so popular, that the teachers later gave up their break room for the kids to have a "computer room" to learn in, completely outfitted by Apple and donations).
Anyhow - I had a TV for a monitor, cassette tape for storage, and a few cartridges (Canyon Climber and Reactoid were my favorite - though later in my teenage years I would discover Dungeons of Daggorath).
I typed in tons of BASIC programs from magazines and books, and yes - finding things incompatible was both frustrating, but informative. I took to learning how to convert between BASICs - GWBasic, PCjr BASIC, and AppleSoft Basic were all fairly easy - for the most part - to convert from so as to run on the Color Computer.
Forget anything for the C=64 or Vic-20, as most of them used tons of POKEs and the special sprite hardware to get anything done, and were (for a kid) impossible to understand what was going on or being done.
I also learned how to convert some code from Fortran to BASIC - I had found a book of graphics code in Fortran, and wanted to run the programs myself...so I learned.
Later, I found a book that detailed how to convert BASIC programs from one system to another; that also assisted me. But ultimately, it was a case of trial and error, tons of reading about the different systems graphics modes, etc.
I still own all of my old computers; I'll keep 'em until I die, I suppose.
I wonder if there's a modern equivalent to this discovery process? I mean that low level systems that require diy and exploration are more thin on the ground. Even a $35 raspberry pi has layers of abstraction many layers higher, and the fact that tablets and phones are much more frequently the first personal computer a kid may own means they don't even need to be exposed to diy systems like the pi, whereas a few decades ago there was no choice.
Don't get me wrong, access to tech is much better, and that's great. I just think it's a different experience than in the past. Not necessarily bad, just... Different